In medical technology, systems based on nuclear spin resonance are used for image generation, like for example magnetic resonance systems (MR) or devices for the magnetic navigation (MN) of probes within the body. System of this type known for example from the previously mentioned DE 102 03 372 A1 require magnetic fields, some of a variable nature, with extremely high field intensities of up to 0.1 Tesla for MN systems and 3 Tesla for MR systems.